def no_teen_sum(a,b,c):
  if a >= 13 and a <=19 and a!=15 and a!=16:
    a=0
  if b >= 13 and b <=19 and b !=15 and b!=16:
    b=0
  if c >= 13 and c <=19 and c !=15 and c!=16:
    c=0
  return a+b+c